429421 square lube groove. Hard to cast or not?

[Bagdadjoe]

I have a chance of buying a Lyman pb 429421 to go with the same in a gc I already have...it has the square shouldered lube groove. Are these picky about dropping bullets?
I've been pondering the 250-KT as well...any advice?

[beagle]

I have a couple of SG 429421s and they cast right well. I've polished the cavity with spray-on moly followed by much polishing with a soft pine stick. Both drop with one or two whacks. Not as bad as some moulds I've encountered (the 429303). The answer is, yes, they do hang a bit but it can be overcome with some polishing beforehand and the result is worth it./beagle

[WallyM3]

Oh, gawd! Somebody had to go and mention the 429303.

My hand still hurts from last night.

[MT Gianni]

Mine have not been picky.

[WallyM3]

You mean the 429303s?

In truth, I have three moulds that throw that boolit. One is a dream, but is a modified Lyman that is a two cherry mould. The second is an aluminum 2-cav chucked up in the mill roght now for much needed surgery. The last, an unimproved Lyman 2-cav virgin-original requires the severest persuasion to yield drops. Those thusly gotten are lovely indeed, but a might's work. I'll be polishing this week.

[Shuz]

The issue with the 429303, is that the grease grooves are soooo small and deep. I never felt so good as when I got rid of mine! The best thing about that design is the Lyman 303 top punch which will work with just about any .44 cal boolit with little or no deforming of the nose.
Now back to the original question: In my experience the square groove 429421 is somewhat harder to get the boolits to drop than the round groove design. Sharp angles have that problem. As Beagle says, it can be mitigated, but in my experience, I never got the square groove design to shoot with any better accuracy than the round groove design, so why bother with the extra whacks? In my opinion, the square groove 429421 is "caught up" in the old Elmer Keith nostalgia thingy.

[94Doug]

I've cast with several this past year, and never had an issue.

Doug

[HeavyMetal]

used both Nephew has the sq groove 4 banger, once up to temp and broken in, the cavities on a "steel" mold should have a slight Blue tint to them if broken in correctly, castings fall just as easily from round to square and I have used both at the same time.

Buy the sq groove 4 banger if the price is not "vintage" and have fun.

As for accuracy? I cound never tell the difference but better shooters might.

[Bagdadjoe]

Thanks to all...

[rintinglen]

The issue with the 429303, is that the grease grooves are soooo small and deep. I never felt so good as when I got rid of mine! The best thing about that design is the Lyman 303 top punch which will work with just about any .44 cal boolit with little or no deforming of the nose.
Now back to the original question: In my experience the square groove 429421 is somewhat harder to get the boolits to drop than the round groove design. Sharp angles have that problem. As Beagle says, it can be mitigated, but in my experience, I never got the square groove design to shoot with any better accuracy than the round groove design, so why bother with the extra whacks? In my opinion, the square groove 429421 is "caught up" in the old Elmer Keith nostalgia thingy.

My opinion as well. I prefer the round groove. With postwar lubes, you don't need a wash tub full to lube a boolit, and any claimed advantage for the square cut versus the round cut lube groove is hypothetical, not real, at least IME.

[enfieldphile]

I have had an RCBS 44-250KT two-cavity mold for 30 years. It casts and drops them fine.

I don't use that design anymore. I now use TC w/ a BB Design for wheel guns and autos both.


The older molds seem to need a little “help” to drop but the newer clones
are more user friendly !

http://www.fototime.com/E574E14FBE964F2/orig.jpg

The RCBS 250-KT (SWC) drops very nicely !

Jerry

[MtGun44]

Not.

Bill